Mortise-lock.



A. LAWRENCE.

MORTISE LOCK. APPLIOATION FILED MAY 29, 1906.

Patented Feb. 22, 1910.

2 SHEETS-SHEET l.

[NVENTUR Altar me A. LAWRENCE.

MORTISE LOCK.

APPLICATION FILED MAY 29, 1906.

2 SHEETS-SHEET 2.

950,108. Patented Feb.22, 1910.

1N VEN T OR 'onrrnn sra rns arana orrron- ALFRED LAWRENCEOF STAMFORD,CONNECTICUT, ASSIGNOR-TO TIi-IE YALE 8a TOW-NE MANUFACTURING COMPANY, OFSTAMFORD, CONNECTICUT.

MORTISE-LOCK.

Specification of Letters Patent.

Patented Feb. 22, 1910.

Application filed. May 29, 1906. Serial No. 319,319.

To all whom it may concern:

Be it known that I, ALFRED LAWRENCE, of Stamford, in the county ofFairfield and State of Connecticut, have invented certain new and usefulImprovements in Mortise- Locks; and I do hereby declare the following tobe a full, clear and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same.

My invention relates to an improvement in mortise locks, the objectbeing to provide a lock wherein the latch bolt may be dogged againstmovement by the outer knob, and the slide, which dogs the outer knob, beitself dogged, so as to prevent a release of same by the pressure of anyinstrument 1ntroduced between the strike plate and the face of the lock,thus absolutely preventing a retraction of the latch bolt from the outside, except by the use of the proper key.

\Vith these ends in view my invention consists in the parts andcombinations of parts as will be more fully explained and pointed out inthe claim. I

In the accompanying drawings, Figure 1 is a View of the lock with theremovable side of the casing removed, showing the dogging plate, whichis carried by the removable side, dogging the outer knob locking slide.Fig. 2 is a similar view showing the dogging plate in the position itoccupies when the door is open, and Fig. 3 is a view of the removableside of the casing showing the plate thereon.

In the drawings I have shown a spring latch bolt 1, that can beretracted by a key through the pivoted bell crank levers 2 and 8 thelatter engaging the bolt near its head, and by inner and outer knobs,each knob being mounted on its own shaft, the two shafts being locatedend to end and connected so as to prevent endwise separation. Each knobshaft is mounted in a roll back, adapted to engage shoulders 4 on thesliding carriage 5, the said shoulders 4 engaging the cross head 6 onthe rear end of the bolt shank, for moving the bolt rearwardly. Inaddition to these parts the lock shown has an auxiliary bolt 7 whichlatter engages the strike plate and is forced inwardly as the door isclosing and remains so while the door is closed. The sliding movement ofthis auxiliary bolt releases a spring pressed dog 8 the end 9 of whichengages a shoulder 10 on the latch bolt and dogs the latter thuspreventing the bolt from being retracted by the introduction of a thinblade or other instrument between the face plate of the lock and thestrike plate. The dog is connected to the key and knob actuatedmechanisms, so that when either knob or key is turned, the end of thedog will be withdrawn from the path of the bolt, thus permitting thelatter to be retracted.

The roll back of the outer knob is provided with a projecting flange 12having a recess 13 for the reception of the free end of the stop workwhich comprises slide 14 having a push button end 14 and an idle slide15 having a similar push button end, the two slides being connected bythe pivoted lever 16, so that when slide 14 is in and is dogging theroll back of the outer knob, slide 15 will be out and by pushing thelatter in the slide 14 will be withdrawn from recess 13 thus leaving thebolt free to be retracted by the outer knob.

The construction thus far described is old and is simply referred to, inorder to show up the defect which my improvement is designed to remedy,and also to make clear the operation of the look as a whole.

WVith this construction the bolt is positively deadlocked againstmovement, by the insertion of a thin blade or other instrument betweenthe face plate of the lock and the strike plate, and the bolt may bedeadlocked against the outer knob, by the slide 14, but no provision hasbeen made for preventing this dead-locking device for the outer knob,from being thrown off by pushing in slide 15, which can be done by aninstrument inserted between the face and strike plates.

This invention therefore consists in means for deadlocking the slide 14either in its in or out position, and it comprises a sliding plate 17plate of the lock. This plate is provided at its end with a toe 18 whichlatter is adapted to enter the slot 19 formed in a projection from slide14 when the latter is dogging the outer knob roll back, and absolutelyprevent any endwise movement of said slide, and consequent release ofthe dogging mechanism by any manipulations from the outside of the door.The plate 17 is normally held with its toe 18 out of the path ofmovement mounted to slide on the cover of slide 14 by the spring 20, andis provided at its rear end with an incline 21 against.

which the lug 22 on auxiliary bolt 7 bears. The lug 22 normally restsnear the lower end of the incline 21, and as the bolt is pushed inwardlyby its contact with the strike plate of the lock, the lug moving incontact with said incline 21 moves the plate 17, thus carrying the toe18 into either slot 19 thus deadlocking the slide in its in or deadlocking position, or in rear of the projection having the slot 19therein, thus locking the slide in its out position. Hence when the dooris in its closed position the stop-work is positively deadlocked ineither position it happens to be in and cannot be actuated from theoutside.

It is evident that many slight changes might be resorted to in therelative arrangement of parts shown and described without departing fromthe spirit and scope of my invention hence I would have it understoodthat I do not wish to confine myself to the exact construction of partsshown and described, but,

Having fully described my invention what I claim as new and desire tosecure by Letters-Patent, is

In a lock the combination with a-main bolt, an auxiliary bolt, thelatter adapted to be forced inwardly by the closing of the door andremain so while the door is closed, and knob mechanism for retractingthe main bolt, of a longitudinal movable slide adapted to be moved to aposition to deadlock the outer knob, one end of said slide projectingthrough the face plate of the lock, and a sliding plate movedtransversely in one direction by the inward movement of the auxiliarybolt and provided with a toe adapted to engage the dead locking slideand prevent it from being moved longitudinally, and a spring for movingsaid sliding plate away from the deadlocking slide.

In testimony whereof. I have signed this specification in the presenceof two subscribmg witnesses.

ALFRED LAVVRENOE.

Witnesses WM. P. MosELY, SGHUYLER MEnRrr'r.

